(Dow Jones) Wealthy Americans who cut back on charitable giving because of the economic downturn are looking for ways to be more disciplined and objective with their philanthropy.

Many high-net-worth families are having to come to terms with reduced income and investments.

"They are saying, 'I want to give the same amount as I did in the past, but I can't,'" according to Bruce Bickel, head of private foundation management services and a senior vice president at PNC Wealth Management.

More than one in four wealthy Americans has felt obliged to cut their giving in the past two years, according to the 2010 PNC Wealth and Values Survey out this week.

At the same time, more than half of these philanthropists say they feel an obligation to give back to their communities.

Bickel says taking the emotion out of giving and focusing on what he calls mission-mindedness can help in the adjustment.

He helps PNC Wealth Management's clients create a set of values and a mission statement about their giving. Then, he says, they devise a points-based scoring system to grade each potential donation from a scale of, say, one to five, based on how the donation would fulfill their mission statement.

"Making decisions based on a disciplined points system removes the guilt," he said. "It helps them focus on what they do have rather than complaining about what they don't have."

One family Bickel works with decided to narrow down the charities they supported based on geography, since supporting their local communities was important to the family's members. They created a system that gave three points to charities in Pennsylvania, where the founders lived, two to charities in West Virginia and one to organizations in Kentucky.

Now, when a charity from Arizona calls for a donation, the family can say the charity is outside their geographical giving parameters, Bickel said.

"Every donation is urgent. We help differentiate between what is urgent and what is important," he said.

Not only are wealthy Americans cutting back on giving, they also are reconsidering the causes they support. About one in five changed the types of organizations or causes to which they give, according to the PNC survey of more than 1,000 adults with more than $500,000 in investable assets.

Over the past two years, the size of the biggest charitable donations have also shrunk significantly, PNC said. Donations ranging from $25,000 to under $1 million now make up almost a third of all donations, while gifts of $1 million or more have shrunk to less than 1% from 15% two years earlier.

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